Textile and Apparel Science

Relationship between Structural Firefighter Protective Clothing Ease and Heat Loss

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Abstract

Heat strain and overexertion have been the number one cause of acute firefighter fatalities since the National Fire Protection Association (NFPA) began collecting such data almost 50 years ago. A firefighter's structural turnout suit ensemble protects against thermal, liquid, and chemical threats through multiple fabric and garment layers of varying thickness and material properties. The purpose of this research was to determine how the fit of bulky garment layers impacts heat transfer through the multi-layer firefighting clothing system. Four sets of industry-recognized turnout suits were obtained in sizes appropriate to an ANDI dynamic sweating thermal manikin. Chest ease allowances were evaluated at 6", 8", 10", and 12". Alterations were made in the chest and adjusted throughout the remainder of the upper body and torso. The full systems ensemble was assessed on a sweating thermal manikin minus the self-contained breathing apparatus. Thermal insulation (Rt) and evaporative resistance (Ret) measurements were collected using ASTM F1291 and 2370 test methods. The predicted manikin total heat loss (THL) was calculated for each turnout suit ensemble of various ease measurements. A three-dimensional body scanner was also utilized to determine the total air gap volume and distance between the base layer and each turnout suit when worn on the body. Findings indicate that a reduction in internal ease measurements increases the amount of heat the body is able to lose to the external environment, to a point. At the 6" internal ease measurement fit limitations were realized in the upper chest and neck areas of the coat. Results provide a valid recommendation for turnout gear manufacturers to potentially reduce internal ease measurements to improve firefighter heat loss and safety.

Keywords: Firefighter, Thermal comfort, Protective clothing, Heat stress, Manikin

How to Cite:

Riedy, R., McQuerry, M. & Schofield, S., (2024) “Relationship between Structural Firefighter Protective Clothing Ease and Heat Loss”, International Textile and Apparel Association Annual Conference Proceedings 80(1). doi: https://doi.org/10.31274/itaa.17742